The present invention relates to a system and method for the preparation of beverages and, in particular, to the use of sealed cartridges which are formed from substantially air- and water-impermeable materials and which contain one or more ingredients for the preparation of beverages.
It has previously been proposed to seal beverage preparation ingredients in individual air-impermeable packages for use in beverage machines. For example, cartridges or capsules containing compacted ground coffee are known for use in certain coffee preparation machines which are generally termed “espresso” machines. In the production of coffee using these preparation machines the coffee cartridge is placed in a brewing chamber and hot water is passed though the cartridge at relatively high pressures, thereby extracting the aromatic coffee constituents from the ground coffee to produce the coffee beverage. Typically, such machines operate at a pressure of greater than 6×105 Pa. The preparation machines of the type described have to date been relatively expensive since components of the machine, such as the water pumps and seals, must be able to withstand the high pressures.
In WO01/58786 there is described a cartridge for the preparation of beverages which operates at a pressure generally in the range 0.7 to 2.0×105 Pa. However, the cartridge is designed for use in a beverage preparation machine for the commercial or industrial market and is relatively expensive.
It is known to provide dairy-based beverage ingredients in cartridges in the form of a powder or other dehydrated form. However, consumers consistently indicate that the use of such powdered dairy-based products adversely affects the taste, colour and texture of the final beverage. In addition, powdered dairy products cannot be used to produce an authentic looking frothy milk-based foam as desired by consumers for cappuccino-style beverages. A number of beverage preparation machines provide a steam wand or similar for frothing of a quantity of milk. However, the addition of the steam wand increases the cost of the machine and requires a means for generating steam. Operation of the steam wand must be done manually and requires experience to be successful. In addition, since steam is being used there is the potential for the consumer to be burnt by either the steam or hot components of the machine. Further, the consumer must keep a supply of milk available separate from the machine and carry out a further process step of a different type in order to produce a cappuccino style beverage. This increases the complexity and time required to produce such beverages.
Hence, there remains a requirement for a system for the preparation of beverages wherein the cartridges and beverage preparation machine of the system are suitable, in particular, for the domestic market in terms of cost, performance and reliability. There is also a need for a beverage preparation machine for such a system which is simple to operate and reliable in operation and can produce a wide range of beverage types.